Web page scrolling issues

I keep getting unusual scrolling behaviour. I try to scroll down a page, but it jumps back to the top. Sometimes if I scroll straight to the bottom and then start scrolling up, the page jumps back to the bottom.
This happens on Midori, Icecat and Firefox, though not so far on Abrowser (only installed about 20 minutes ago) and happens on some pages, but not on others. When it happens the page is unreadable.

Anyone experienced similar behaviour?
(I'm using Trisquel 7)